Kim Kardashian has apologized to Apple bosses after huge demand for her new emoji app allegedly caused the company's online store to crash.

The reality TV star announced the launch of her Kimoji program on social media on Sunday, ahead of its Monday release, and fans flocked to download the animated keyboard, which features emojis of her lips, her hand raising a middle finger and her face with contour makeup lines.

However, some devotees were left disappointed on Monday as they encountered technical difficulties locating the program on Apple's App Store, which reportedly struggled to handle the surge in popularity.

Kanye West's wife went on to assure followers glitches within the app itself would soon be corrected.

"We worked so hard on this app & we know there are some issues due to the massive downloads that the whole tech team is so working on!" she continued. "My Kimoji app will be up and running again soon! They are also working on fixing the search so u (sic) can easily find it!"

We worked so hard on this app & we know there are some issues due to the massive downloads that the whole tech team is so working on!

The Kimoji app also features animated versions of some of the Keeping Up With the Kardashians beauty's most viral Internet photos, including her famous crying face and a selfie she took of her reflection in a mirror, capturing her curves from behind as she modelled a revealing white one-piece bathing suit.

The new mum, who welcomed her second child, a son named Saint, earlier this month, has already proved to be a mobile mogul with her recent Kim Kardashian West app, which gives fans a behind-the-scenes look at her daily life, and Kim Kardashian: Hollywood, an online game which raked in US$74 million.